1. Field of the Invention
The invention relates to a coupling device for maximum pressure-tight threaded pipe connectors with a standard coupling body with a 24 degree connector, a coupling nut, to effect a pressure-tight connection, a standard pipe or a connection stub for connection to other system components and a two-part ring whereby one ring takes the form of a holding element, preferably a cutting or clamping ring.
2. Description of the Prior Art
For the manufacture of coupling devices for pressure-tight threaded couplings, the use of a two-part ring acting as a cutting or clamping ring is prior art. DIN 4000 Part 36, Number 13, for example, describes a double wedge ring which comprises two separate wedge or clamping rings which, when being tightened, work together in overlapping timed sequence. It is thus not possible for the fitter to determine positively the end of the fitting process, with the resultant inability to exclude faulty fitting. At the very least, considerable experience on the part of the fitter of the force processes developed in the coupling device during tightening is called for, if the incidence of faulty fitting is to be reduced or eliminated.
A threaded pipe sleeve coupling is known from DE-PS 12 53 531 which is provided with two consecutively arranged compression washers which are caused to dig in to the wall of the pipe which they enclose. Here again the problems described above are encountered during fitting as the forces applied to the two rings overlap and the stage the tightening has reached cannot be positively registered. In addition considerable force has to be exerted during fitting to overcome frictional forces.